Hearing loss varies widely from patient to patient in type and severity. As a result, the acoustical characteristics of a hearing aid must be selected to provide the best possible result for each hearing impaired person. Typically, these acoustical characteristics of a hearing aid are “fit” to a patient through a prescription procedure. Generally, this has involved measuring hearing characteristics of the patient and calculating the required amplification characteristics based on the measured hearing characteristics. The desired amplification characteristics are then programmed into a digital signal processor in the hearing aid, the hearing aid is worn by the patient, and the patient's hearing is again evaluated while the hearing aid is in use. Based on the results of the audiometric evaluation and/or the patient's comments regarding the improvement in hearing, or lack thereof, an audiologist or dispenser adjusts the programming of the hearing aid to improve the result for the patient.
As one would expect, the fitting procedure for a hearing aid is generally an interactive and iterative process, wherein an audiologist or dispenser adjusts the programming of the hearing aid, receives feedback from the patient, adjusts the programming again, and so forth, until the patient is satisfied with the result. In many cases, the patient must evaluate the hearing aid in various real world situations outside the audiologist's or dispenser's office, note its performance in those situations and then return to the audiologist or dispenser to adjust the hearing aid programming based on the audiologist's or dispenser's understanding of the patient's comments regarding the patient's experience with the hearing aid.
One of the significant factors in the price of a hearing aid is the cost of the audiologist's or dispenser's services in fitting and programming the device, along with the necessary equipment, such as software, computers, cables, interface boxes, etc. If the required participation of the audiologist and/or dispenser and the fitting equipment can be eliminated or at least significantly reduced, the cost of a hearing aid can be significantly reduced.
The complexity and cost of fitting hearing assistance devices in general also applies in the fitting of tinnitus masking devices. Tinnitus is a condition wherein a person experiences a sensation of noise (as a ringing or roaring) that is caused from a condition, such as a disturbance of the auditory nerve, hair cells, temporal mandibular joint or medications, to name a few. Tinnitus is a significant problem for approximately 50 million people each year, and some people only find relief with tinnitus maskers. A tinnitus masker looks like a hearing aid, but instead of amplifying sensed sound, it produces a sound, such as narrow-band noise, that masks the patient's tinnitus. Some of these instruments have a trim pot that is used to change the frequency of the masking noise. Such instruments may also have a volume control so the user may select the intensity of the masking that works best.
Most tinnitus maskers are prescribed to patients who do not have significant hearing loss, and the masking sound is designed to be more acceptable to the patient than the tinnitus. For most patients that have significant hearing loss, hearing aids can also provide tinnitus relief. However, there are some patients that need both amplification and tinnitus masking.
The most appropriate masking stimuli to be generated by a tinnitus masker is usually determined by an audiologist or dispenser during a fitting procedure. Like the fitting of a hearing aid, the fitting procedure for a tinnitus masker also tends to be an iterative process which significantly increases the overall cost of the masking device.
What is needed, therefore, is a programmable hearing assistance device that does not require a fitting procedure conducted by an audiologist or dispenser. To obviate the necessity of the programming equipment and the necessity of an audiologist or dispenser fitting procedure, a programmable hearing assistance device is needed which is automatically programmed based on selections made by a patient while using the device or based on usage patterns of the patient. This need applies to hearing aids as well as to tinnitus masking devices.